What is the max CBR if you add fly ash to the soil?
What is the max CBR if you add fly ash to the soil?
(OP)
I just got a CBR of 125 with 12% fly ash added to the soil. Is that even possible?
LL = 50; PL = 12; PI = 38. USCS = CL/CH. We added the fly ash, waited 10 minutes, compacted to target density, waited 2 hours, soaked 4 days and tested.
I was trying to determine the design CBR for when the project gets going. The client wanted 20-25, and estimated we would need to add 15-18% fly ash to get that.
Thanks in advance
M-I-Z
LL = 50; PL = 12; PI = 38. USCS = CL/CH. We added the fly ash, waited 10 minutes, compacted to target density, waited 2 hours, soaked 4 days and tested.
I was trying to determine the design CBR for when the project gets going. The client wanted 20-25, and estimated we would need to add 15-18% fly ash to get that.
Thanks in advance
M-I-Z





RE: What is the max CBR if you add fly ash to the soil?
RE: What is the max CBR if you add fly ash to the soil?
RE: What is the max CBR if you add fly ash to the soil?
hokie66, I agree with the constant supervision required in the field. I was just shocked at the in-lab value.
More info about the material: the proctors were done per ASTM D1557 "Modified"; we ran the proctor with fly ash according to D558 but compacted it in 5 layers with the bigger rammer (keep it modified per project specs); the CBR was then compacted to 90% MDD with %moisture at 5% over optimum (close to field conditions)
Most material I have read states to expect a maximum CBR of around 30. So, 125 seems to have surpassed that just slightly.
RE: What is the max CBR if you add fly ash to the soil?
f-d
¡papá gordo ain't no madre flaca!
RE: What is the max CBR if you add fly ash to the soil?
Maybe the tyranny of Murphy is the penalty for hubris. - http://xkcd.com/319/